共查询到20条相似文献,搜索用时 78 毫秒
1.
复系数2n阶微分算子的谱 总被引:4,自引:0,他引:4
本文研究了复系数2n阶微分算式(2.1)生成的J-自伴微分算子谱,对两类微分算子的本质谱,离散谱作了定性研究,得到了所生成微分算子本质谱的存在范围,以及所生成微分算子的谱是离散的充分条件. 相似文献
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证明了n阶行列式一阶微分为其逐次微分之和,进而得到了Wronsky行列式及其一阶微分的关系. 相似文献
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奇摄动时滞反应扩散方程 总被引:1,自引:0,他引:1
研究了一类带有小延迟的微分-差分反应扩散方程初值边值问题.在适当的条件下,利用伸长变量法,构造了问题的形式渐近解.再用微分不等式理论证明了解的一致有效性. 相似文献
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微分对策求解往往涉及到困难的两点边值问题(TPBV),将线性二次型微分对策问题归结于Hamilton体系.对Hamilton系统,辛几何算法具有能复制Hamilton系统的动态结构并保持相平面上的测度的优点.从Hamilton系统角度,探讨了线性二次型微分对策系统的辛性质;作为尝试,对无限期间线性二次型微分对策的计算引入Symplectic-Runge-Kutta算法.给出了一个数值计算实例,从结果可以说明这种方法的可行,也体现了辛算法对系统的能量具有良好的守恒性. 相似文献
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本文利用纳依玛克 ~[1]的方法研究了 2n阶非对称微分算子(J-对称微分算 子);得到一类极限点型的非对称微分算子(J-对称微分算子). 相似文献
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根据微分中值定理和积分中值定理定义微分点与积分点.证明严格单调函数与凸(凹)函数中微分点与积分点间的一些关系式,指出在函数对称的情况下微分点与积分点之间也存在着对称关系,并给出一类向量函数以及多项式函数中微分点与积分点间的关系式. 相似文献
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本文在一般的Banach空间中研究非凸微分包含的生存问题.我们首先构造出了上述非凸微分包含的一个生存集.然后给出了所构造的生存集的两个应用. 相似文献
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Joanna Goard 《Applicable analysis》2013,92(5):473-481
It is generally believed that in order to solve initial and boundary value problems using Lie symmetry methods, the boundary and initial conditions need to be left invariant by the infinitesimal symmetry generator which admits the invariant solution. In this article we give less restrictive conditions on the imposed initial and boundary values in order that they be recoverable with a particular symmetry generator. 相似文献
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利用Avery-Henderson不动点定理,研究了含积分边界条件的二阶边值问题正解的存在性,推广了以往的结果. 相似文献
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A class of quasilinear Robin problems with boundary perturbation are considered. Under suitable conditions, using theory of differential inequalities the asymptotic behavior of solution for the boundary value problem is studied. 相似文献
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Djuro M. Misljenovic 《Applied Mathematical Modelling》1982,6(3):205-208
In this paper the boundary integral expression for a one-dimensional wave equation with homogeneous boundary conditions is developed. This is done using the time dependent fundamental solution of the corresponding hyperbolic partial differential equation. The integral expression developed is a generalized function with the same form as the well-known D'Alembert formula. The derivatives of the solution and some useful invariants on the characteristics of the partial differential equation are also calculated.The boundary element method is applied to find the numerical solution. The results show excellent agreement with analytical solutions.A multi-step procedure for large time steps which can be used in the boundary element method is also described.In addition, the way in which boundary conditions are introduced during the time dependent process is explained in detail. In the Appendix the main properties of Dirac's delta function and the Heaviside unit step function are described. 相似文献
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Martin V. Day 《Applied Mathematics and Optimization》2006,53(3):359-381
Neumann or oblique derivative boundary conditions for viscosity solutions of Hamilton-Jacobi equations are considered. As
developed by P.L. Lions, such boundary conditions are naturally associated with optimal control problems for which the state
equations employ "Skorokhod" or reflection dynamics to ensure that the state remains in a prescribed set, assumed here to
have a smooth boundary. We develop connections between the standard formulation of viscosity boundary conditions and an alternative
formulation using a naturally occurring discontinuous Hamiltonian which incorporates the reflection dynamics directly. (This
avoids the dependence of such equivalence on existence and uniqueness results, which may not be available in some applications.)
At points of differentiability, equivalent conditions for the boundary conditions are given in terms of the Hamiltonian and
the geometry of the state trajectories using optimal controls. 相似文献
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源于膨胀波边界层理论中的一类奇异边值问题 总被引:1,自引:0,他引:1
对源于膨胀波边界层理论中的一类奇异边值问题进行了研究,利用单调逼近方法得到了满足物理意义上正解的存在性和唯一性的充分条件,同时给出了用速度比例参数表示的壁摩擦的估计公式, 利用打靶法技巧得到了问题的数值解.数值结果证明了估计公式的可靠性和有效性. 相似文献
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The article is concerned with the boundary controllability of non-linear stochastic differential inclusions in a Banach space. Sufficient conditions for the boundary controllability are obtained by using a fixed point theorem for condensing maps due to Leray–Schauder non-linear alternative. 相似文献
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研究了带有积分边值条件的分数阶微分方程的边值问题.利用LeggettWilliams不动点定理,以及一些分析技巧得到了这类分数阶微分方程边值问题多个正解的存在性. 相似文献
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声波的散射问题中,如果散射体由不可穿透障碍物和可穿透裂缝两部分组成,障碍物表面分别满足第一类和第三类边界条件,裂缝两边满足不同的第二类边界条件,通过位势理论,可以将此混合问题转化为边界积分方程,通过Fredholm算子理论可以得到这个边界积分方程解的存在性和唯一性,从而获得原问题解的存在和唯一性. 相似文献